If you think about it the only surprising thing about this astronaut kidnapping story is that it, or something similar, hasn't happened previously.
The astronaut corps is made up of people who are driven. They spend their entire life in pursuit of that goal. They are a group of individuals who refuse to take no for an answer by profession. Of all the type A personalities they are the type A-iest.
It seems to me it would only take a few neurons firing in the wrong direction for somebody with that personality to extend that trait into their personal life in a destructive manner. It was only a matter of time.